code: def test_init(self):
      self.assertIsInstance(
          self.decoder.hybrid_decoder, SequenceAttentionDecoder
      )
      self.assertIsInstance(
          self.decoder.position_decoder, PositionAttentionDecoder
      )
      hybrid_decoder = dict(
          type="SequenceAttentionDecoder", max_seq_len=40
      )
      position_decoder = dict(type="PositionAttentionDecoder")
      with self.assertWarns(Warning):
          RobustScannerFuser(
              dictionary=self.dict_cfg,
              module_loss=self.loss_cfg,
              hybrid_decoder=hybrid_decoder,
              position_decoder=position_decoder,
              max_seq_len=40,
          )
      hybrid_decoder = dict(
          type="SequenceAttentionDecoder", dictionary=self.dict_cfg
      )
      with self.assertWarns(Warning):
          RobustScannerFuser(
              dictionary=self.dict_cfg,
              module_loss=self.loss_cfg,
              hybrid_decoder=hybrid_decoder,
              position_decoder=position_decoder,
              max_seq_len=40,
          )
  
file_path: mmocr/tests/test_models/test_textrecog/test_decoders/test_robust_scanner_fuser.py
imports: from unittest import TestCase
  import torch
  from mmengine.structures import LabelData
  from mmocr.models.textrecog.decoders import PositionAttentionDecoder, RobustScannerFuser, SequenceAttentionDecoder
  from mmocr.structures import TextRecogDataSample
label_desc: Use image node_id 2 for calling the TestRobustScannerFuser obj's underlying member method code with example usage: obj.test_init() without return types